Transformer tank

ABSTRACT

In a transformer tank the bottom is strengthened by cutting out rectangular plates with tapered edges so that the plates have the shape of truncated pyramids. The plates are placed under the holes formed when the plates are cut out of the bottom, the largest flat surface of each plate facing the side of the bottom where each hole is smallest. The plates are then welded to the bottom.

United States Patent Inventor Robert Koranyi [56] References Cited Ludvlkz, Swede" UNITED STATES PATENTS g gs 233 1969 1,131,367 3/1915 Greason 220/71 x Patented Oct 19, 1971 1,722,149 7/1929 Kubler 220/71 X Assignee Allnlanna Svenska Elektriska Aktiebolaget Primary Examiner-Lloyd L. King Vasteras, Sweden Attorney-Jennings Bailey, Jr. Priority Dec. 5, 1968 Sweden s g g f 2? ABSTRACT: In a transformer tank the bottom is strengthened 4 C alms rawmg by cutting out rectangular plates with tapered edges so that (1.8. CI 2211/71, the plates have the shape of truncated pyramids. The plates 29/155, 29/416, 29/482 are placed under the holes formed when the plates are cut out Int. Cl B6511 7/42 of the bottom, the largest flat surface of each plate facing the Field of Search 220/7l; side of the bottom where each hole is smallest. The plates are 29/416, 15, 155, 482 then welded to the bottom.

3 I IZ/ZQZ/ \l /'//l PATENTEDUBT 19 I 3,613,941

2 3 v 2 3 W/A 1 ////'///1 INVENTOR. ROBERT KORANYI TRANSFORMER TANK BACKGROUND OF THE INVENTION l. Field of the Invention The invention relates to the manufacture of transformer tanks.

2. The Prior Art When manufacturing transformer tanks, several factors must be taken into consideration, particularly concerning the bottom of the tank. It must be made so strong that it carries the core with windings without bending too much. At the same time its height must be as little as possible in view of the available transport when moving the finished transformer. The bottom construction now universally used consists of a single plate having a thickness of 25 60 mm., which is too heavy if it is sufficiently strong. Special steel has even been used with an increased yield point, in order to obtain a bottom having less thickness, but the bending is too great since the elasticity module is more or less the same for most types of steel.

SUMMARY OF THE INVENTION The present invention relates to a transformer tank, the bottom of which is considerably strengthened by means of a special method of manufacture, without the quantity of material increasing. The invention is characterized in that at least from the bottom of the tank preferably rectangular plates are out having tapered edges so that the plates are shaped like truncated pyramids and in that the plates are placed under the hole formed when the plate is cut out of the sheet metal, the largest flat surface of the plate facing the side of the sheet metal where the hole is smallest and that the plates are welded to the sheet metal.

A bottom plate according to the invention has a total height which is twice the thickness of the plate. However, the height required for transport of the transformer will be the same as for a single plate since the feet of the transformer core are positioned in the recesses of the bottom plate. The bending resistance of the bottom is increased twofold and the moment of inertia fourfold, the quantity of metal being unaltered. These provides a cheaper construction, lower building height and lower transport weight, these being properties of increasing importance, the larger the unit.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 shows a cross section of the bottom of a tank according to the invention.

FIG. 2 shows the bottom seen from above.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A bottom manufactured according to the invention consists of a plate 1 with dimensions corresponding to the size of the tank. From the metal plate a number of preferably rectangular plates 2 are cut. The plates are cut out with oblique burners so that they are shaped as truncated pyramids. The plates cutout are then placed so that they cover the holes, the side of the plate having the greatest surface being placed against the side of the plate where the hole 3 has the smallest area. The plates 2 are then welded to the plate I. The plates are cut out and welded on so their longitudinal direction is parallel to the transverse direction of the bottom 1.

An approximate measurement of the width of the plates cu tout may be stated as 400-500 mm. The length depends on the width of the tank since the rectangular plates are positioned with their longitudinal direction across the longitudinal direction of the bottom and extend almost to the long sides of the bottom.

I claim:

1. A wall for a transformer tank comprising a main plate having openings therein with tapered edges, and smaller plates having substantially the same outer dimensions as the inner dimensions of the o enin welded on the face of the late into which the smal er en s of the openings emerge wit the larger faces of the smaller plates welded to such face of the main plate and overlapping the edges of the openings of all sides.

2. A wall as claimed in claim 1 in which the openings are rectangular.

3. A wall as claimed in claim I which is substantially greater in one direction than in the other and in which the openings are substantially greater in length in a direction perpendicular to the greater dimension of the wall than in the other direction.

4. A wall as claimed in claim 3 in which the width of the opening at its larger end is 400-500 mm. 

1. A wall for a transformer tank comprising a main plate having openings therein with tapered edges, and smaller plates having substantially the same outer dimensions as the inner dimensions of the openings welded on the face of the plate into which the smaller ends of the openings emerge with the larger faces of the smaller plates welded to such face of the main plate and overlapping the edges of the openings of all sides.
 2. A wall as claimed in claim 1 in which the openings are rectangular.
 3. A wall as claimed in claim 1 which is substantially greater in one direction than in the other and in which the openings are substantially greater in length in a direction perpendicular to the greater dimension of the wall than in the other direction.
 4. A wall as claimed in claim 3 in which the width of the opening at its larger end is 400-500 mm. 